This Core Laboratory will provide support in five areas: (1) to produce, maintain, and characterize antibodies, (2) to analyze genomic DNA by polymerase chain reaction, (3) to analyze and to quantitate cellular mRNA, (4) to provide histopathology, immunohistochemistry, and in situ hybridization support, and (5) to maintain bacterial culture and plasmid stocks. (1st Core Area). Western blots are used to characterize antibody specificity and cross reactivity to pancreatic lipases, cholesterol esterase, phospholipase A/2, and to lipid binding proteins though to be involved in lipid uptake by the epithelial cells of the small intestine. These antibodies are used in Western blots, enzyme linked immunosorbent assays, and in immunohistochemical studies to measure changes in protein amount and location that occur in tissues and fluids in response to dietary manipulations, gene knock out, and ectopic expression of pancreatic lipase. (2nd Core Area). The progeny of targeted gene knock out mice are genotyped by polymerase chain reaction. Genotyping of human DNA is performed to assess apoE alleles and apoA-IV alleles in a population of potential study patients. (3rd Core Area). Cellular mRNA for human low density lipoprotein receptor and for hydroxymethylglutaryl CoA reductase is characterized by reverse transcription polymerase chain reaction. The changes in mRNA responses to dietary manipulations are characterized. Additionally, in mice the impact of knock out or of ectopic expression of pancreatic lipase on dietary regulated expression of pancreatic lipases and cholesterol esterase is characterized. (4th Core Area). We will provide support services for histopathological studies, immunohistochemical studies, and in situ hybridization studies of tissues. (5th Core Area). We will maintain and distribute bacterial cultures and plasmid stocks in this Core.